European Journal of Radiology

Editorial Board

2012-02-01

Malignant spiculated breast masses: Dynamic contrast enhanced MR (DCE-MR) imaging enhancement characteristics and histopathological correlation

Gokhan Gokalp, Ugur Topal, Nalan Yildirim, Sahsine Tolunay — 2012-02-01

Abstract: Aim: Spiculation of breast masses is usually the result of significant desmoplastic reaction. Diminished neovascularization is expected due to sparsely dispersed tumor cells within the lesion. This feature can cause differences in enhancement patterns which can cause pitfalls while evaluating MR images as well. Aim of this study is to explore the enhancement characteristics of malignant spiculated masses and to correlate these findings with histopathological features.Materials and methods: Eighteen spiculated and seventeen non-spiculated masses depicted with mammography were included in the study. MR imaging was performed with 1.5T magnet with breast coil. In MR imaging, T2-weighted turbo spin echo (TSE) with fat suppression sequence followed by pre- and post-contrast T1-weighted 3D-fast low angle shot (FLASH) sequences were used. Lesions were evaluated according to enhancement characteristics: early phase enhancement (first 2min; less than 50%, 50–100% and more than 100%), late phase enhancement (2–6min; persistent, plateau and washout) and inner enhancement pattern (homogenous, heterogenous and rim). Desmoplasia and lymphocyte infiltration was classified as mild, moderate and severe. MR images and histopathological findings (desmoplasia, lymphocyte infiltration and grade) of both groups were compared.Results: Mean ages of patients in spiculated and non-spiculated-mass groups were 55.07 (41–71) and 47.35 (31–62), respectively. Mean diameter of lesions was 17.3mm (10–31mm) for spiculated masses while non spiculated masses were 15.8mm (6–40mm). There were statistically significant differences between late phase enhancement, persistent enhancement, plateau and washout (p<0.05). Intergroup comparison of desmoplasia revealed significant difference between severe versus and mild, moderate (p<0.05).Conclusion: Spiculated malignant lesions are supposed to contain intense desmoplastic reaction. On DCE-MR images they can show persistent enhancement pattern more often than non-spiculated lesions.

The negative predictive value of breast Magnetic Resonance Imaging in noncalcified BIRADS 3 lesions

M.D. Dorrius, R.M. Pijnappel, P.E. Sijens, M.C. Jansen van der Weide, M. Oudkerk — 2012-02-01

Abstract: Purpose: The purpose of this study is to determine whether breast MRI can provide a sufficient NPV to safely rule out malignancy in mammographic BIRADS 3 lesions.Materials and methods: In a 3-year consecutive mammographic examination study 176 out of 4391 patients had a lesion classified as BIRADS 3. 76 out of 176 patients underwent breast MRI as diagnostic work-up. Lesions which MRI classified as BIRADS 1 or 2 were considered negative for malignancy. Sensitivity, specificity, PPV and NPV were calculated.Results: In 27 out of 76 (35.5%) patients MRI showed no enhancement and was classified as BIRADS 1. In 25 (32.9%) patients MRI showed focal or mass enhancement classified as BIRADS 2. In these 52 (68.4%) patients no malignancy was found during at least 2 years study follow-up. The other 24 (31.6%) patients had a lesion classified as BIRADS ≥3. Thirteen of these 24 lesions were malignant by pathology. MRI had a sensitivity of 100% (95% CI: 75–100%), specificity of 82.5% (95% CI: 71–91%), PPV of 54.2% (95% CI: 33–74%) and NPV of 100% (95% CI: 93–100%).Conclusion: Breast MRI should be used in a diagnostic strategy for the work-up of noncalcified BIRADS 3 lesions. Malignancy is ruled out with a very high level of confidence in the majority of patients (68%), herewith avoiding invasive diagnostic procedures.

MRI morphological classification of ductal carcinoma in situ (DCIS) correlating with different biological behavior

Haiquan Liu, Weijun Peng — 2012-02-01

Abstract: Objective: To investigate morphological appearance of ductal carcinoma in situ of breast on MRI and to correlate the appearances with some factors.Methods and materials: MRI feature of 41 DCISs were analyzed retrospectively according to ACR BI-RADS, twenty-three of the 41 were pure DCIS and 18 were DCIS with microinvasion (DCIS-MI). The shape was categorized as mass lesion and non-mass-like lesion. The shape was correlated with histological grade, ER status and expression of e-erbB2 as well as pure DCIS or DCIS-MI.Results: Percentage of high grade in non-mass-like lesion was higher than that in mass type group, Average size of tumor in group of high grade, negative ER status and positive c-erbB2 expression were larger than that in non-high grade, positive ER status and negative c-erbB2 expression. Comparing pure DCIS and DCIS-MI, high grade in DCIS-MI was significantly higher than that in pure DCIS, Average size of DCIS-MI was larger than that in pure DCIS. Percentage of non-mass-like lesion was higher in DCIS-IM than that in pure DCIS, the difference was marginally significant.Conclusion: DCIS can be classified as mass type and non-mass-like type morphologically on MRI. The two types reflect different biological behavior.

Comparison of automated 4-chamber cardiac views versus axial views for measuring right ventricular enlargement in patients with suspected pulmonary embolism

2012-02-01

Abstract: Purpose: Compare the right ventricle to left ventricle (RV/LV) diameter ratio obtained from axial pulmonary CT angiograms (CTPA) with those derived from automatically generated 4-chamber (4-CH) reformats in patients with suspected pulmonary embolism (PE).Methods: In this institutional review board-approved study we included 120 consecutive non ECG-gated CTPA from 3 institutions (mean age 60±16 years; 71 women). Twenty 64-slice CTPA with PE and 20 without PE were selected per institution. For each patient the RV/LV diameter ratio was obtained from both axial CTPA images and automatically generated 4-CH reformats. Measurements were performed twice in two separated sessions by 2 experienced radiologists and 2 residents. The differences between the measurements on both views were evaluated.Results: The 4-CH view was successfully obtained in 113 patients. The mean axial and 4-CH diameter ratios were comparable for three of the four readers (p=0.56, p=0.13, p=0.08). Although the mean diameters (1.0 and 1.03 respectively) for one resident were significantly different (p=0.013), the difference of 0.03 seems negligible in clinical routine. Three readers achieved equally high intra-reader agreements with both measurements (ICCs of 0.94, 0.95 and 0.96), while one reader showed a different variability with ICCs of 0.96 for the axial view and 0.91 for the 4-CH view. The inter-reader agreement was equally high for both measurement types with ICCs of 0.95 and 0.94, respectively.Conclusion: In patients with suspected PE, RV/LV diameters ratio can be measured with the same reproducibility and accuracy using an automatically generated 4-CH view compared to the axial view.

A comparative analysis of double inversion recovery TFE and TSE sequences on carotid artery wall imaging

Jun Chen, Yu-Jin Di, Chun-Qing Bu, Yan-Feng Zhang, Shu-Hua Li — 2012-02-01

Abstract: Objective: To analyze the characteristics of double inversion recovery (DIR) turbo field echo (TFE) and turbo spin echo (TSE) sequences and explore the value of double inversion recovery TFE sequence on carotid artery wall imaging.Patients and methods: 56 patients (32 males and 24 females, aged 31–76 years with a mean age of 53 years) were performed with DIR TFE and DIR TSE T1 weighted imaging (T1WI) sequences on carotid artery bifurcations. Image quality acquired by different techniques were evaluated and scored by two physicians. Whether there is significant difference is determined by SPSS 11.0 software. Paired-samples t test was used for statistics.Results: There was no significant difference in the image quality scores between two sequences (t=0.880, P=0.383>0.05).Conclusions: DIR TFE sequence has short scanning time and high spatial resolution. DIR TFE sequence can be used as the preferred sequence for screening carotid atherosclerotic plaque compared with DIR TSE sequence.

Can left ventricular end-diastolic volumes be estimated with prospective ECG-gated CT coronary angiography?

Prateek J. Khatri, Vikas Tandon, Li Chen, Yeung Yam, Benjamin J.W. Chow — 2012-02-01

Abstract: Background: With the goal of minimizing patient radiation exposure, many centres have adopted prospective ECG-gated computed tomographic coronary angiography. Since image acquisition occurs only during ventricular diastasis, the ability to measure left ventricular (LV) ejection fraction (EF) and LV volumes has been lost. Given that LV volumes have prognostic value, the ability to estimate LV end diastolic volume (EDV) may be clinically desirable.Objective: We sought to predict LV EDV using CT coronary angiography (CTA) images obtained during ventricular diastasis.Methods: Consecutive patients who underwent retrospective ECG-gated CTA were enrolled. Images were reconstructed at the 75% phase and at end-diastole. LV and left atrial (LA) volumes were measured.Results: A total of 153 consecutive patients were analyzed (mean age=56.7±11.2 years; men=56.2%). The mean LV EDV and EF were 144.4±40.2mL and 63.4±9.9%, respectively. There appeared to be a very strong linear relationship between the 75% phase LV volume and LV EDV with an R2 of 0.993. Using LV and LA volumes at the 75% phase, a prediction model of LV EDV was developed (LV EDV=(1.021×75% phase LV volume)+(0.259×75% phase LA volume), adjusted R2=0.995).Conclusion: LV EDV can be estimated using CTA data obtained during ventricular diastasis. Further studies are needed to demonstrate that such estimates of LV EDV have incremental prognostic value over coronary artery disease severity assessment with prospective ECG-gated CTA.

Influence of hemodynamic parameters on coronary artery attenuation with 320-detector coronary CT angiography

2012-02-01

Abstract: Objectives: To investigate the relationship between cardiac output, end diastolic volume and the contrast enhancement in coronary CT angiography using 320-detector CT.Materials and methods: A total of 38 patients underwent coronary CT angiography by using a 320-detector CT scanner (detector configuration, 320×0.5mm). The attenuation value of the ascending aorta at the level of the orifice of the left main trunk was measured. The cardiac output (CO), end diastolic volume (EDV) and stroke volume (SV) were measured by echocardiography. The EDV was normalized to the body surface area (BSA). The total blood volume injected from the left ventricle from the beginning of the contrast agent injection to the time of image acquisition was determined to be the total injected blood volume (TIV), which is a product of SV and the number of heart beats from the initiation of contrast agent injection to the scan.Results: There was a negative correlation between the attenuation of the ascending aorta and CO (r=−0.44, P=0.0053). However, the negative correlation between the attenuation of the ascending aorta and TIV was stronger (r=−0.52, P=0.0007). There was a negative correlation between the attenuation of the ascending aorta and EDV/BSA (r=−0.45, P=0.0039).Conclusion: In 320-detector CT, contrast enhancement in CCTA with a lesser amount of contrast medium decreases when cardiac output is high. Patients with larger EDV/BSA may also show decreased attenuation.

Estimation of the left ventricular diastolic function with cardiac MDCT: Correlation of the slope of the time-enhancement-curve with the mitral annulus diastolic velocity

2012-02-01

Abstract: Patients with diastolic heart failure tend to have a poor outcome, similar to that for patients with systolic heart failure. The aim of this study was to explore the ability of MDCT to estimate the left ventricular diastolic function.Thirty patients with suspected coronary artery disease underwent MDCT and echocardiography. The early transmitral flow velocities (E) and the velocity of mitral annulus early diastolic motion (e′) were measured in order to evaluate the diastolic function. The scanning delay of CT was determined using a test injection technique. The aortic enhancement was measured over the aortic-root lumen, and it was plotted over time to yield a time-enhancement-curve. A gamma variate function was then fit to the time-enhancement-curve and thereafter both the ‘slope’ of enhancement for each patient and the region of interest [ROI] were calculated.According to a univariate analysis, the slope of the time-enhancement-curve was found to correlate with the e′ (r=0.686, P=0.000) and E/e′ (r=−0.482, P=0.007), however, no significant correlation was observed with the systolic parameters of the left ventricle.These results indicate that the slope of the time-enhancement-curve in the aorta significantly correlates with e′, i.e. the diastolic parameters, which are independent of the systolic parameters. Based on these findings, we propose that the slope of the time-enhancement-curve may serve as a parameter for the left ventricular diastolic function on MDCT.

MR-imaging of the thoracic aorta: 3D-ECG- and respiratory-gated bSSFP imaging using the CLAWS algorithm versus contrast-enhanced 3D-MRA

2012-02-01

Abstract: Objective: To compare a contrast-enhanced 3D angiography (CE-3D-MRA) with the ECG- and respiratory gated 3D balanced steady state free precession (bSSFP) sequence using the CLAWS algorithm (3D-bSSFP-CLAWS) with respect to acquisition time, image quality, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR).Methods: 14 patients (4 women, mean age±SD: 52±18) with known or suspected thoracic aortic disease were imaged on a 1.5T scanner with both sequences. Two readers scored image quality of predefined levels of the thoracic aorta. Acquisition time, SNR and CNR were calculated for each examination.Results: Image quality achieved with the 3D-bSSFP-CLAWS was scored significantly better than with the CE-3D-MRA for the aortic annulus (P=0.003), the sinuses of Valsalva (P=0.001), the proximal coronary arteries (P=0.001) and the sinotubular junction (P=0.001). Effective acquisition time for the 3D-bSSFP-CLAWS and corrected acquisition time (corrected for imaging parameters) was significantly longer compared to the CE-3D-MRA (P=0.004 and P=0.028). SNR and CNR were significantly higher for the CE-3D-MRA (P=0.007 and P=0.001).Conclusions: Providing the highest scan efficiency for a given breathing pattern, image quality for the proximal ascending aorta achieved with the 3D-bSSFP-CLAWS is significantly superior in contrast to the CE-3D-MRA.

Non- invasive in vivo analysis of a murine aortic graft using high resolution ultrasound microimaging

2012-02-01

Abstract: Introduction: As yet, murine aortic grafts have merely been monitored histopathologically. The aim of our study was to examine how these grafts can be monitored in vivo and non-invasively by using high-resolution ultrasound microimaging to evaluate function and morphology. A further aim was to prove if this in vivo monitoring can be correlated to immunohistological data that indicates graft integrity.Methods: Murine infrarenal aortic isografts were orthotopically transplanted into 14 female mice (C57BL/6-Background) whereas a group of sham-operated animals (n=10) served as controls. To assess the graft morphology and hemodynamics, we examined the mice over a post-operative period of 8 weeks with a sophisticated ultrasound system (Vevo 770, Visual Sonics).Results: The non-invasive graft monitoring was feasible in all transplanted mice. We could demonstrate a regular post-transplant graft function and morphology, such as anterior/posterior wall displacement and wall thickness. Mild alterations of anterior wall motion dynamics could only be observed at the site of distal graft anastomosis (8 weeks after grafting (transplant vs. sham mice: 0.02mm±0.01 vs. 0.03mm±0.01, p<0.05). However, the integrity of the entire graft wall could be confirmed by histopathological evaluation of the grafts.Conclusions: With regard to graft patency, function and morphology, high resolution ultrasound microimaging has proven to be a valuable tool for longitudinal, non-invasive, in vivo graft monitoring in this murine aortic transplantation model. Consequently, this experimental animal model provides an excellent basis for molecular and pharmacological studies using genetically engineered mice.

Time-resolved contrast-enhanced magnetic resonance angiography (CEMRA) of the left atrium–pulmonary veins complex with half dose of intravenous gadolinium-based contrast agent. Technical feasibility and comparison with a conventional CEMRA, full contrast dose protocol

2012-02-01

Abstract: Purpose: To evaluate feasibility and image quality of time-resolved contrast-enhanced magnetic resonance angiography (CEMRA) of the left atrium–pulmonary veins (LA–PV) complex with half dose of intravenous gadolinium-based contrast agent (GBCA) in patients candidate to percutaneous radiofrequency ablation of atrial fibrillation.Methods and materials: Fifty-seven patients underwent CEMRA of the LA–PV complex on a 1.5T MRI scanner. On 24/57 patients, a conventional fast-spoiled gradient-echo (FSPGR) CEMRA acquisition was run using 0.2mL/kg of 0.5M GBCA at 2mL/s flow rate (protocol A), while in 33/57 patients a time-resolved multiphase CEMRA sequence (Time-Resolved Imaging of Contrast KineticS, TRICKS) was performed after intravenous injection of 0.1mL/kg of the same GBCA at 3mL/s flow rate (protocol B). Contrast enhancement was measured in the LA (LAe) and in the PA (PAe), and the LAe/PAe ratio was calculated. Diagnostic quality of Maximum Intensity Projection (MIP), Volume Rendering (VR), and Virtual Endoscopy (VE) reconstructions was also assessed visually using a semiquantitative score.Results: LAe was comparable with both protocols, while PAe was lower with protocol B than with protocol A (p=0.0217). Moreover, the LAe/PAe ratio was significantly higher with protocol B than with protocol A (p=0.0044).Finally, image quality of MIP, VR, and VE reconstructions was significantly better with protocol B than with protocol A (p=0.0005, p=0.0001, and p=0.005, respectively).Conclusions: CEMRA of the LA–PV complex is feasible with TRICKS and half-dose GBCA and yields better separation between the LA–PV complex and the PA, as well as better image quality of MIP, VR, and VE reconstructions than a conventional FSPGR sequence performed with full GBCA dose.

Usefulness of ultrafast dynamic 3D-T1w data acquisition in detection of hypervascular lesions of the middle ear: First experience

René Aschenbach, Steffen Basche, Dirk Eßer, Thomas Josef Vogl — 2012-02-01

Abstract: Objective: To evaluate ultrafast dynamic 3D-T1w acquisition for improved detection of tympanic hypervascularized lesions.Methods: Retrospective evaluation of a total of 50 patients referred from ENT-Department for suspected tympanic lesion. All underwent magnetic resonance imaging including ultrafast dynamic 3D-T1w acquisition imaging. Quantitative and qualitative evaluation was performed as well as statistical analysis. Comparison with intra-operative results.Results: 12/50 patients showed a hypervascularized lesion proved intraoperative as 8 paragangliomas, 2 adenoms, 1 hemangioma and 1 neurinoma. 8/50 do not show hypervascularization though an enhancement was detected. Intra-operative granulation tissue was found. 30 patients did not show any lesions or enhancement. Sensitivity and specificity was 100%/100% for ultrafast dynamic imaging.Conclusion: Additional ultrafast dynamic 3D-T1w imaging is superior to conventional imaging in detection of hypervascularized lesions.

Whole-body magnetic resonance angiography for presurgical planning of free-flap head and neck reconstruction

2012-02-01

Abstract: Objectives: Aim of the study was to evaluate if a whole-body magnetic resonance angiography (MRA) protocol meets the requirements to evaluate the donor and host site target vessels for planning of microvascular head and neck reconstructions.Patients and methods: In 20 patients, scheduled for reconstruction of the mandible with fibular free flaps, contrast-enhanced whole-body MRA was performed prior to surgery. 32-Channel 1.5-T MR angiograms were acquired using a 2-step contrast (gadobutrol) injection scheme to visualize the arterial vasculature from head to feet. Maximum intensity projection and multiplanar reconstruction technique was employed to visualize MRA data. For image evaluation the arterial tree was divided into 51 segments. The presence of artefacts impairing diagnostic quality was noted. Evaluable segments were assessed regarding the presence of stenoses >50% diameter reduction, occlusions or aneurysms.Results: No adverse reactions or complications occurred. Of 1020 vessel segments 1003 (98.3%) were evaluable. 36 stenoses >50%, 50 occlusions and one aneurysm were observed. In 21 of 40 lower limbs relevant atherosclerotic changes were depicted.Conclusion: Whole-body MRA proved to be a suitable three-dimensional, noninvasive, nonionising modality for preoperative evaluation of the entire arterial vasculature.

Effective dose range for dental cone beam computed tomography scanners

2012-02-01

Abstract: Objective: To estimate the absorbed organ dose and effective dose for a wide range of cone beam computed tomography scanners, using different exposure protocols and geometries.Materials and methods: Two Alderson Radiation Therapy anthropomorphic phantoms were loaded with LiF detectors (TLD-100 and TLD-100H) which were evenly distributed throughout the head and neck, covering all radiosensitive organs. Measurements were performed on 14 CBCT devices: 3D Accuitomo 170, Galileos Comfort, i-CAT Next Generation, Iluma Elite, Kodak 9000 3D, Kodak 9500, NewTom VG, NewTom VGi, Pax-Uni3D, Picasso Trio, ProMax 3D, Scanora 3D, SkyView, Veraviewepocs 3D. Effective dose was calculated using the ICRP 103 (2007) tissue weighting factors.Results: Effective dose ranged between 19 and 368μSv. The largest contributions to the effective dose were from the remainder tissues (37%), salivary glands (24%), and thyroid gland (21%). For all organs, there was a wide range of measured values apparent, due to differences in exposure factors, diameter and height of the primary beam, and positioning of the beam relative to the radiosensitive organs.Conclusions: The effective dose for different CBCT devices showed a 20-fold range. The results show that a distinction is needed between small-, medium-, and large-field CBCT scanners and protocols, as they are applied to different indication groups, the dose received being strongly related to field size. Furthermore, the dose should always be considered relative to technical and diagnostic image quality, seeing that image quality requirements also differ for patient groups. The results from the current study indicate that the optimisation of dose should be performed by an appropriate selection of exposure parameters and field size, depending on the diagnostic requirements.

Susceptibility-weighted imaging of the brain: Does gadolinium administration matter?

2012-02-01

Abstract: Objective: Susceptibility-weighted MR imaging (SWI) is usually obtained without administration of intravenous gadolinium (Gd). However, it is occasionally necessary to perform SWI after Gd is injected. The effects of Gd on SWI have not been systematically examined. The aim of this prospective study was to investigate whether performing SWI after Gd would influence the diagnostic image quality, parenchymal signal and vascular enhancement. An additional aim is to suggest potential future applications for Gd-enhanced SWI.Methods: SWI was performed in 31 subjects before and after Gd administration. 17 cases were examined in a 1.5T scanner and the remaining 14 were scanned at 3T. The pre- and post-Gd images were analysed for signal changes in the cerebral grey matter (GM), white matter (WM) as well as for enhancement in the superficial and deep venous system. The visibility of the veins was graded on subtraction maps.Results: The Gd-enhanced images showed no image quality degradation and no significant signal intensity change in the GM and WM as compared to the pre-Gd images (p>0.05). After Gd-administration significant enhancement of the venous sinuses was noticed (p<0.005), while the deep and cortical veins were poorly enhanced as confirmed by the calculated subtraction maps. The results showed no significant difference at variable MRI field strengths.Conclusion: It is possible to perform SWI after Gd injection without information loss or signal change in the parenchyma. The most significant difference is the enhancement of the cerebral venous sinuses. Potential future applications are discussed.

Changes in thalamus connectivity in mild cognitive impairment: Evidence from resting state fMRI

2012-02-01

Abstract: Purpose: The subcortical region such as thalamus was believed to have close relationship with many cerebral cortexes which made it especially interesting in the study of functional connectivity. Here, we used resting state functional MRI (fMRI) to examine changes in thalamus connectivity in mild cognitive impairment (MCI), which presented a neuro-disconnection syndrome.Materials and methods: Data from 14 patients and 14 healthy age-matched controls were analyzed. Thalamus connectivity was investigated by examination of the correlation between low frequency fMRI signal fluctuations in the thalamus and those in all other brain regions.Results: We found that functional connectivity between the left thalamus and a set of regions was decreased in MCI; these regions are: bilateral cuneus, middle occipital gyrus (MOG), superior frontal gyrus (SFG), medial prefrontal cortex (MPFC), precuneus, inferior frontal gyrus (IFG) and precentral gyrus (PreCG). There are also some regions showed reduced connectivity to right thalamus; these regions are bilateral cuneus, MOG, fusiform gyrus (FG), MPFC, paracentral lobe (PCL), precuneus, superior parietal lobe (SPL) and IFG. We also found increased functional connectivity between the left thalamus and the right thalamus in MCI.Conclusion: The decreased connectivity between the thalamus and the other brain regions might indicate reduced integrity of thalamus-related cortical networks in MCI. Furthermore, the increased connectivity between the left and right thalamus suggest compensation for the loss of cognitive function. Briefly, impairment and compensation of thalamus connectivity coexist in the MCI patients.

The value of strain ratio in differential diagnosis of thyroid solid nodules

2012-02-01

Abstract: Objective: To assess the clinical value of strain ratio in differentiating thyroid solid nodules and explore its distribution characters based on pathological results.Materials and methods: The study was approved by the ethic committee and the informed consents were signed. Ninety nine solid thyroid nodules (67 benign and 32 malignant) from 71 female (mean age 46.3±9.8 years) and 28 male (mean age 54.9±11.7 years) patients were evaluated. Five radiologists evaluated the nodules based on a four-degree elastography score system. Strain ratio was calculated on-line. Diagnostic performances of the two evaluations were compared using Receiver Operating Characteristic (ROC) curves. Values of different pathological nodules were compared by one-way ANOVA.Results: Areas under the ROC curve (AUC) of the five readers were 0.82, 0.81, 0.79, 0.73 and 0.83, respectively. The AUC of strain ratio evaluation was higher (0.88 vs. 0.79, p<0.001) than that of the ES score evaluation. Best cut-off points of the two evaluations were 3.5 (82% sensitivity, 72% specificity) and 4.225 (81% sensitivity, 83% specificity), respectively. Both the ES score and strain ratio were higher for malignant nodules than that for benign ones (p<0.001).Conclusions: Strain ratio was a useful index in differential diagnosis of thyroid solid nodules. It can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence. The best cut-off point for benign and malignant nodules was 4.2.

Hyperintensity on diffusion weighted image along ipsilateral cortical spinal tract after cerebral ischemic stroke: A diffusion tensor analysis

2012-02-01

Abstract: Purpose: Hyperintensity along the ipsilateral cortical spinal tract (CST) on a diffusion weighted imaging (DWI) has been reported to may be associated with motor disability after brain infarction and can be misdiagnosed as a new infarction. However, the underlying patho-physiology related to this finding is not clear. The goal of our study was to analyze the diffusion tensor imaging (DTI) changes in patients with this hyperintensity.Materials and methods: Eight patients (50±10 years) who exhibited hyperintensity on DWI along ipsilateral CST from 3 to 21 days after stroke onset were reviewed as positive group, including 5 patients with serial DTI examinations. Twelve patients without hyperintensity during the matched examination time were classified as reference group. The apparent diffusion coefficient (ADC), fractional anisotropy (FA), and eigenvalues and their ratios (ipsilateral/contralateral value) in cerebral peduncle were measured, their correlation with motor function scale at eight months after stroke onset were evaluated.Results: The serial examinations showed that hyperintensity could eventually disappear. Both the ipsilateral ADC and FA values were significantly decreased (p<0.05) compared to the contralateral side. The ipsilateral FA significantly correlated with motor function scale in both groups (r=0.875, 0.738; p=0.004, 0.006 respectively).Conclusions: The hyperintensity on DWI is a transient pathological process of Wallerian degeneration after ischemic stroke, its diffusion characteristics include concurrent significant decrease of ipsilateral ADC and FA. The ipsilateral FA value has the potential to predict neurological motor function outcome in such patients.

Clinical utility of quantitative magnetic resonance angiography in the assessment of the underlying pathophysiology in a variety of cerebrovascular disorders

Jonathan L. Brisman, John Pile-Spellman, Angelos A. Konstas — 2012-02-01

Abstract: Background: Quantitative MRA (qMRA) is a relatively new technique that uses traditional time-of-flight and phase-contrast MRI to visualize extracranial and intracranial vascular anatomy and measure volumetric blood flow. We aimed to assess the clinical utility of qMRA in assessing the hypothesized pathophysiology (HP) in a range of cerebrovascular diseases. Moreover, we postulated that evaluation of the arterial waveforms, can improve the evaluation of the hypothesized pathophysiology by qMRA.Methods: We reviewed studies from 10 patients who underwent qMRA examinations before and after their treatments. Two reviewers assessed the anatomy, volumetric flow rates and arterial waveforms for each vessel sampled and reached a consensus as to whether the above parameters supported the clinical diagnosis/hypothesized pathophysiology and the subsequent management.Findings: All 20 qMRA studies were technically adequate. qMRA supported the HP in all 10 patients as determined by abnormal volumetric flow values in the affected vessels before treatment and by the correction of these abnormal values in the patients whose treatment was successful. Each of our five patients with occlusive disease/vasoconstriction demonstrated evidence of dampening of the arterial waveforms distally to the narrowed artery (parvus–tardus phenomenon). The parvus–tardus effect disappeared after treatment.Conclusion: qMRA is unique in combining time-of-flight MRA in a complementary manner with phase-contrast MRA to obtain volumetric flow values and potentially important physiologic information from arterial waveform analysis in patients with a range of cerebrovascular diseases during the course of a single MR examination.

18F-FDG PET, combined FDG-PET/CT and MRI for evaluation of bone marrow infiltration in staging of lymphoma: A systematic review and meta-analysis

Lian-Ming Wu, Fang-Yuan Chen, Xiao-Xing Jiang, Hai-Yan Gu, Yan Yin, Jian-Rong Xu — 2012-02-01

Abstract: Background and purpose: Evaluation of bone marrow infiltration is an essential step in the staging of lymphoma. The accuracy of 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET), combined 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) and magnetic resonance imaging (MRI) in diagnosing bone marrow involvement of lymphoma has never been systematically assessed, and the present systematic review was aimed at this issue.Methods: MEDLINE, EMBASE, Cochrane library and some other databases, from January 1995 to July 2010, were searched for initial studies. All the studies published in English or Chinese relating to the diagnostic value of 18F-FDG PET, PET/CT and MRI for patients with bone marrow involvement of lymphoma were collected. We extracted data to calculate sensitivity, specificity, SROC curves and AUC and to test for heterogeneity. The statistic software called “Meta-Disc 1.4” was used for data analysis.Result: In 32 included studies, PET/CT had the highest pooled sensitivity, 91.6% (95%CI: 85.1, 95.9) and highest pooled specificity, 90.3% (95%CI: 85.9, 93.7). PET/CT also had the highest pooled DOR, 68.89 (95%CI: 15.88, 298.92). The AUC of PET, PET/CT, and MRI were 0.9430, 0.9505 and 0.8764. There was heterogeneity among studies and no evidence of publication bias.Conclusion: PET/CT was a highly sensitive and specific modality in diagnosing patients with bone marrow involvement in lymphoma. Compared with MRI and PET alone, PET/CT can play important roles in the staging of lymphoma.

Radiographic study of the hip joint to determine anthropometric parameters for Indian population

2012-02-01

Abstract: Hip replacement surgeries are on the rise in India. However, for these surgeries, most of the implants used are imported and manufactured entirely to suit the geometrical considerations of the western population. Studies in the past have shown that there are anatomical variations in the hip joint for different ethnic backgrounds and geographical locations. There is paucity of anthropometric hip joint data related to Indian population and anthropometric variations in skeletal geometry between Asian and Western counterparts have not yet been thoroughly reviewed and considered for implant manufacturing.The purpose of this anthropometric study is to determine any anatomical variations in the normal hip joint among the Indian population and to statistically compare the mean values with the existing data on western population.422 Hip radiographs of 211 individuals (141 males and 70 females) with normal and healthy hip joints were evaluated to obtain the horizontal offset, vertical offset and neck shaft angle. For males, mean neck shaft angle was 127.68° (SD=3.94), horizontal offset was 34.60mm (SD=6.55) and vertical offset was 39.17mm (SD=5.86). For females, mean neck shaft angle was 125.92° (SD=4.75), horizontal offset was 32.96mm (SD=7.04) and vertical offset was 36.38mm (SD=6.28).When these parameters were compared to the data available from western world, there were significant anatomical variations and it was evident that there is a need to evaluate existing implants in relation to this data and possibly design the implants suited and relevant to Indian population.

Ultrasound characteristics of gouty tophi in the olecranon bursa and evaluation of their reproducibility

2012-02-01

Abstract: Objectives: To describe the ultrasound characteristics of gouty tophi in the olecranon bursa and to evaluate their reproducibility.Methods: A prospective study of the ultrasound features of 35 sites of tophi nodulations in the elbows of 31 men (mean 54.6 years). The findings were evaluated dynamically following pre-established standards. The static images were evaluated by another radiologist and were reviewed by the first examiner.Results: The most frequent characteristics of tophi are: hyperechogenicity (91.7%), poorly defined contours (88.6%), multiple grouped nodules (85.6%) and heterogeneity (68.6%). Intra-observer agreement is almost perfect for echogenicity (K=1.0), moderate for the involvement of the olecranon bursa (K=0.47) and fair for other characteristics. Inter-observer agreement is substantial for the echogenicity (K=0.65), fair for the echotexture (K=0.27) and the presence of a perilesional hypoechoic halo (K=0.34) and slight for other characteristics.Conclusions: The most frequent characteristic of tophi is hyperechogenicity. The intra-observer and inter-observer concordance for echogenicity are almost perfect and substantial, respectively. Knowledge of characteristics of the tophi in the elbow and their intra and inter-observer reproducibility may assist in establishing parameters for monitoring treatment and setting up criteria for differential diagnosis of processes involving the olecraneon bursa.

Quantitative T2 evaluation at 3.0T compared to morphological grading of the lumbar intervertebral disc: A standardized evaluation approach in patients with low back pain

2012-02-01

Abstract: Background: The purpose of our investigation was to compare quantitative T2 relaxation time measurement evaluation of lumbar intervertebral discs with morphological grading in young to middle-aged patients with low back pain, using a standardized region-of-interest evaluation approach.Patients and methods: Three hundred thirty lumbar discs from 66 patients (mean age, 39 years) with low back pain were examined on a 3.0T MR unit. Sagittal T1-FSE, sagittal, coronal, and axial T2-weighted FSE for morphological MRI, as well as a multi-echo spin-echo sequence for T2 mapping, were performed. Morphologically, all discs were classified according to Pfirrmann et al. Equally sized rectangular regions of interest (ROIs) for the annulus fibrosus were selected anteriorly and posteriorly in the outermost 20% of the disc. The space between was defined as the nucleus pulposus. To assess the reproducibility of this evaluation, inter- and intraobserver statistics were performed.Results: The Pfirrmann scoring of 330 discs showed the following results: grade I: six discs (1.8%); grade II: 189 (57.3%); grade III: 96 (29.1%); grade IV: 38 (11.5%); and grade V: one (0.3%). The mean T2 values (in milliseconds) for the anterior and the posterior annulus, and the nucleus pulposus for the respective Pfirrmann groups were: I: 57/30/239; II: 44/67/129; III: 42/51/82; and IV: 42/44/56. The nucleus pulposus T2 values showed a stepwise decrease from Pfirrmann grade I to IV. The posterior annulus showed the highest T2 values in Pfirrmann group II, while the anterior annulus showed relatively constant T2 values in all Pfirrmann groups. The inter- and intraobserver analysis yielded intraclass correlation coefficients (ICC) for average measures in a range from 0.82 (anterior annulus) to 0.99 (nucleus).Conclusions: Our standardized method of region-specific quantitative T2 relaxation time evaluation seems to be able to characterize different degrees of disc degeneration quantitatively. The reproducibility of our ROI measurements is sufficient to encourage the use of this method in future investigations, particularly for longitudinal studies.

Imaging of endolymphatic hydrops in Meniere's disease at 1.5T using phase-sensitive inversion recovery: (1) Demonstration of feasibility and (2) overcoming the limitations of variable gadolinium absorption

2012-02-01

Abstract: Endolymphatic hydrops is the primary histopathological finding in Meniere's disease. We demonstrate the feasibility of imaging endolymphatic hydrops at 1.5T using phase-sensitive inversion recovery (PS-IR) MRI following intratympanic injection of gadolinium (Gd). PS-IR data were imaged using real reconstruction to enable visualization of the phase of the signal permitting clear definition between bone, unopacified endolymph and perilymph.Data were obtained 24h following injection in 2 control subjects and in 13 successive patients with Meniere's disease. In 11 out of 13 patients, dilated endolymphatic structures were clearly identified as filling defects within the opacified perilymph allowing identification of endolymphatic hydrops. There was a large range in the degree of perilymphatic signal enhancement due to variability in absorption of Gd from the middle ear into the perilymph. The use of multiple TI values allowed confident identification of endolymphatic hydrops in Meniere's patients even when perilymph opacification was suboptimal at one TI value.This is the first time endolymphatic hydrops has been demonstrated at 1.5T in humans. The methods presented are of significant practical importance and will permit broader application of endolymphatic imaging and may also act to reduce the frequency of failed exams due to inadequate Gd uptake.

Lymphomas and glioblastomas: Differences in the apparent diffusion coefficient evaluated with high b-value diffusion-weighted magnetic resonance imaging at 3T

2012-02-01

Abstract: Background and purpose: As the usefulness of the apparent diffusion coefficient (ADC) obtained from diffusion-weighted images (DWI) for the differential diagnosis between glioblastoma and primary central nervous system lymphoma is controversial, we assessed whether high b-value DWI at b 4000s/mm2 could discriminate between glioblastoma and lymphoma. We also compared the power of high- and standard b-value (b-4000, b-1000) imaging on a 3-Tesla (3T) magnetic resonance (MR) instrument.Materials and methods: This study was approved by our Institutional Review Board. We acquired DWI at 3T with b=1000 and b=4000s/mm2 in 10 patients with lymphoma and 14 patients with glioblastoma. The ADC was measured by placing multiple regions of interest (ROI) on ADC maps of the site of enhanced lesions on contrast-enhanced T1-weighted MR images. We avoided hemorrhagic and cystic lesions by using T1-, T2-, FLAIR-, and T2* MR images. The ADC values of each tumor were determined preoperatively from several ROI and expressed as the minimum-, mean-, and maximum ADC value (ADCMIN, ADCMEAN, ADCMAX). We evaluated the relationship between ADCs and histological information including tumor cellularity.Results: All ADC values were statistically associated with tumor cellularity. ADCMIN at b-4000 was associated with tumor cellularity more significantly than ADCMIN at b-1000. All ADC values were lower for lymphoma than glioblastoma and the statistical difference was larger at b=4000- than b=1000s/mm2. According to the results of discriminant analysis, the log likelihood was greatest for ADCMIN at b=4000. At a cut-off value of ADCMIN=0.500×10−3mm2/s at b-4000 it was possible to differentiate between lymphoma and glioblastoma (sensitivity 90.9%, specificity 91.7%).Conclusions: Calculating the ADC value is useful for distinguishing lymphoma from glioblastoma. The lowest degree of overlapping and a better inverse correspondence with tumor cellularity were obtained with ADCMIN at b-4000s/mm2 at 3T MRI.

Evaluation of right ventricular function by 64-row CT in patients with chronic obstructive pulmonary disease and cor pulmonale

Yan Gao, Xiangying Du, Lei Liang, Lizhen Cao, Qi Yang, Kuncheng Li — 2012-02-01

Abstract: Purpose: The aim of this study was to investigate the clinical application value of right ventricle (RV) function measured by 64 multi-detector row CT (MDCT) in patients with chronic obstructive pulmonary disease (COPD) and cor pulmonale.Materials and methods: Sixty-three consecutive patients with COPD and cor pulmonale were referred for electrocardiographically gated MDCT for evaluation of suspected or known coronary artery disease. Magnetic resonance imaging (MRI) for cardiac function analysis was performed on the same day. The MDCT and MRI examinations were successfully completed in 58 patients. Forty-six patients with COPD were divided into three groups according to the severity of disease by the pulmonary function test (PFT). Twelve patients diagnosed as cor pulmonale and 32 control subjects were also included. The RV function and myocardial mass (MM) were obtained by 64-MDCT and 1.5T cardiac MRI in all of the groups. The results were compared among the groups using the Newman–Keuls method. Pearson's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and MM with the PFT results in COPD and cor pulmonale patients.Results: The RVEF was significantly lower in patients with severe COPD and cor pulmonale than it was in those patients with mild or moderate COPD (P<0.01). There were strong correlations between MDCT and MRI (r=0.826 for RV MM, r=0.982 and 0.969 for RV EDV and RV ESV, r=0.899 for RVEF) and between MDCT results and forced expiratory volume in 1s (r=0.787 for RVEF, r=−0.774 for RV MM) in all patients.Conclusion: MDCT can accurately quantify RV function and MM. The RVEF and RV MM measured by MDCT correlate well with the severity of disease as determined by PFT in patients with COPD and cor pulmonale. The assessment of right ventricular function is clinically important for evaluation of the severity of COPD, which may provide an objective basis for therapeutic strategy.

CT fluoroscopy-guided cutting needle biopsy of focal pure ground-glass opacity lung lesions: Diagnostic yield in 83 lesions

2012-02-01

Research highlights: ▶ I would like to add the following sentence at the end of the paragraph in the section 2.4 statistical analysis: A P value of < 0.05 was considered to be statistically significant. ▶ The lines in Table 3 are out of alignment. Please align them correctly. ▶ In Table 4, three data on Lesion depth in diagnostic failure group and a P value were revealed to be incorrect. I correct them. Please see Table 4.Abstract: Objective: The objective of our study was to retrospectively determine the diagnostic yield of CT fluoroscopy-guided cutting needle biopsy of focal pure ground-glass opacity lung lesions.Materials and methods: Biopsies were performed using 20-G coaxial cutting needles for 83 focal pure ground-glass opacity lung lesions (mean lesion size, 12.1mm). After excluding the lesions for which biopsy specimens were unobtainable and final diagnoses were undetermined, the diagnostic yield, including sensitivity and specificity for a diagnosis of malignancy and accuracy, was calculated. The lesions were then divided into 2 groups: the diagnostic failure group, comprising lesions with false-negative results and for which a biopsy specimen was unobtainable; and the diagnostic success group, comprising lesions with true-negative results and true-positive results. Various variables were compared between the 2 groups by univariate analysis.Results: Biopsy specimens were obtained from 82 lesions, while specimens could not be obtained from 1 lesion. Final diagnosis was undetermined in 16 lesions. The sensitivity and specificity for a diagnosis of malignancy were 95% (58/61) and 100% (5/5), respectively. Diagnostic accuracy was 95% (63/66). The 4 lesions in diagnostic failure group were smaller, deeper, and more likely to be located in the lower lobe and further, for those lesions, number of specimens obtained was smaller, compared with 63 lesions in diagnostic success group. However, none of the differences were statistically significant.Conclusion: CT fluoroscopy-guided cutting needle biopsy provided high diagnostic yield for focal pure ground-glass opacity lung lesions.

Dual Energy CT lung perfusion imaging—Correlation with SPECT/CT

2012-02-01

Abstract: Objective: Aims were (1) to determine the diagnostic accuracy of Dual Energy CT (DECT) in the detection of perfusion defects and (2) to evaluate the potential of DECT to improve the sensitivity for PE.Methods: 15 patients underwent Dual Energy pulmonary CT angiography (DE CTPA) and a combination of lung perfusion SPECT/CT and ventilation scintigraphy. CTPA and DE iodine distribution maps as well as perfusion SPECT/CT and inhalation scintigrams were reviewed for pulmonary embolism (PE) diagnosis. DECT and SPECT perfusion images were assessed regarding localization and extent of perfusion defects. Diagnostic accuracy of DE iodine (perfusion) maps was determined with reference to SPECT/CT. Diagnostic accuracies for PE detection of DECT and of SPECT/CT with ventilation scintigraphy were calculated with reference to the consensus reading of all modalities.Results: DE CTPA had a sensitivity/specificity of 100%/100% for acute PE, while the combination of SPECT/CT and ventilation scintigraphy had a sensitivity/specificity of 85.7%/87.5%. For perfusion defects, DECT iodine maps had a sensitivity/specificity of 76.7% and 98.2%.Conclusion: DECT is able to identify pulmonary perfusion defects with good accuracy. This technique may potentially enhance the diagnostic accuracy in the assessment of PE.

Potential contribution of multiplanar reconstruction (MPR) to computer-aided detection of lung nodules on MDCT

2012-02-01

Abstract: Purpose: To evaluate potential benefits of using multiplanar reconstruction (MPR) in computer-aided detection (CAD) of lung nodules on multidetector computed tomography (MDCT).Materials and methods: MDCT datasets of 60 patients with suspected lung nodules were retrospectively collected. Using “second-read” CAD, two radiologists (Readers 1 and 2) independently interpreted these datasets for the detection of non-calcified nodules (≥4mm) with concomitant confidence rating. They did this task twice, first without MPR (using only axial images), and then 4 weeks later with MPR (using also coronal and sagittal MPR images), where the total reading time per dataset, including the time taken to assess the detection results of CAD software (CAD assessment time), was recorded. The total reading time and CAD assessment time without MPR and those with MPR were statistically compared for each reader. The radiologists’ performance for detecting nodules without MPR and the performance with MPR were compared using jackknife free-response receiver operating characteristic (JAFROC) analysis.Results: Compared to the CAD assessment time without MPR (mean, 69s and 57s for Readers 1 and 2), the CAD assessment time with MPR (mean, 46s and 45s for Readers 1 and 2) was significantly reduced (P<0.001). For Reader 1, the total reading time was also significantly shorter in the case with MPR. There was no significant difference between the detection performances without MPR and with MPR.Conclusion: The use of MPR has the potential to improve the workflow in CAD of lung nodules on MDCT.

Comparative study of clinical, pathological and HRCT findings of primary alveolar proteinosis and silicoproteinosis

2012-02-01

Abstract: Objective: To compare the clinical, high-resolution computed tomography (HRCT) and pathological findings of primary alveolar proteinosis (PAP) and silicoproteinosis.Material and methods: The study included 15 patients with PAP (6 women, 9 men, mean age 31 years) and 13 with silicoproteinosis (13 men, mean age 29.5 years). PAP was diagnosed by lung biopsy in 13 and bronchoalveolar lavage in two patients and silicoproteinosis by bronchoalveolar lavage in 10 and autopsy in three cases. HRCT images were reviewed by two chest radiologists with consensus for the presence, extent and distribution of ground-glass opacities, septal thickening, consolidation and nodules. Radiological–pathological correlation was performed by one radiologist and one chest pathologist.Results: Seven (46%) patients with PAP were asymptomatic; the remainder presented slowly progressive dyspnea and dry cough. All silicoproteinosis patients had dry cough and rapidly progressive dyspnea. The most common HRCT finding on PAP was the crazy-paving pattern (93%). All cases had areas of geographic sparing in the affected lung. The most common finding in silicoproteinosis (92%) was dependent consolidation with calcification in 83%. Centrilobular nodules were common (85%). On pathology, both diseases demonstrated intra-alveolar accumulation of PAS material, thickening of interlobular septae and alveolar walls and no evidence of fibrosis. A few silica particles were seen in silicoproteinosis.Conclusion: Despite the pathological similarities, PAP and silicoproteinosis have distinct clinical and imaging features and prognosis. Bilateral crazy-paving pattern with areas of geographic sparing is characteristic for PAP. Silicoproteinosis presents with bilateral dependent consolidation often with areas of calcification. The crazy-paving pattern is not seen in silicoproteinosis.

Application of adjusted subpixel method (ASM) in HRCT measurements of the bronchi in bronchial asthma patients and healthy individuals

Grzegorz Mincewicz, Jacek Rumiński, Grzegorz Krzykowski — 2012-02-01

Abstract: Background: Recently, we described a model system which included corrections of high-resolution computed tomography (HRCT) bronchial measurements based on the adjusted subpixel method (ASM).Objective: To verify the clinical application of ASM by comparing bronchial measurements obtained by means of the traditional eye-driven method, subpixel method alone and ASM in a group comprised of bronchial asthma patients and healthy individuals.Methods: The study included 30 bronchial asthma patients and the control group comprised of 20 volunteers with no symptoms of asthma. The lowest internal and external diameters of the bronchial cross-sections (ID and ED) and their derivative parameters were determined in HRCT scans using: (1) traditional eye-driven method, (2) subpixel technique, and (3) ASM.Results: In the case of the eye-driven method, lower ID values along with lower bronchial lumen area and its percentage ratio to total bronchial area were basic parameters that differed between asthma patients and healthy controls. In the case of the subpixel method and ASM, both groups were not significantly different in terms of ID. Significant differences were observed in values of ED and total bronchial area with both parameters being significantly higher in asthma patients. Compared to ASM, the eye-driven method overstated the values of ID and ED by about 30% and 10% respectively, while understating bronchial wall thickness by about 18%.Conclusions: Results obtained in this study suggest that the traditional eye-driven method of HRCT-based measurement of bronchial tree components probably overstates the degree of bronchial patency in asthma patients.

Quantitative bronchial luminal volumetric assessment of pulmonary function loss by thin-section MDCT in pulmonary emphysema patients

2012-02-01

Abstract: Objectives: To determine the capability of quantitative bronchial luminal volume to assess pulmonary function loss and disease severity in pulmonary emphysema patients.Methods: Thirty-seven smokers (mean age, 68.1 years) underwent CT examinations and pulmonary function tests. For the quantitative assessment, luminal voxels of trachea and bronchi were computationally counted and the ratio of the following luminal voxels to all luminal voxels was obtained: (1) the lobe bronchi and the peripheral bronchi (Ratiolobe), and (2) the main bronchi and the peripheral bronchi (Ratiomain). To determine the capability of these assessments to predict pulmonary function loss, these ratios were correlated with pulmonary function tests. To determine the capability for predicting disease severity, these ratios were compared between clinical groups.Results: These ratios were no significant correlated with vital capacity and forced vital capacity (FVC) (p>0.05), however significantly correlated with forced expiratory volume in 1s (FEV1) (Ratiolobe: r=0.61, p<0.0001, Ratiomain: r=0.58, p<0.0005) and FEV1/FVC (Ratiolobe: r=0.36, p<0.05, Ratiomain: r=0.33, p<0.05). The Ratiolobe of smokers without COPD was significantly different from those of moderate COPD and severe or very severe COPD (p<0.05), while that of mild COPD was significantly different from that of severe or very severe COPD (p<0.01). The Ratiomain of severe or very severe COPD patients was significantly different from those of other groups (p<0.05).Conclusions: Quantitative bronchial luminal volumes were reflected the airflow limitation parameters and was corresponded to clinical groups in emphysema patients.

Computed tomography findings from patients with ARDS due to Influenza A (H1N1) virus-associated pneumonia

2012-02-01

Abstract: Purpose: The purpose of this study was to retrospectively evaluate whether computed tomography (CT) findings have prognostic value for the prediction of mortality and severity of the clinical course in patients presenting with early stage of acute respiratory distress syndrome (ARDS) due to swine-origin influenza A (S-OIV).Materials and methods: Chest CT (16-/64-row multidetector CT) of 23 patients (of whom 9 patients died) were retrospectively reviewed by three independent blinded observers. The CT findings were graded on a 3-point scale (1: normal attenuation, 2: ground-glass attenuation, 3: consolidation). The extent of each abnormality was determined by visually estimating the percentage (to the nearest 10%) of the affected lung parenchyma in each zone and multiplied by the CT-score described above.Results: All patients presented with a mixture of bilateral patchy consolidations and ground glass opacities. Spearman rank correlation in evaluation of the presence and extent of lung abnormalities by the three different observers was good (correlation coefficient, 0.876–0.922; p<0.001). The overall CT-score in survivors (mean, 96.0 (±26.2); range, 53–158) was significantly lower than that in non-survivors (mean, 116.2 (±14.0); range, 101–139). ROC analysis revealed an area under curve of 0.79 (p=0.021) for the CT score with an optimal cutoff value of a CT-score of 100 for prediction of survival, with a sensitivity of 100% and a specificity of 64% (accuracy, 78%). For this optimal cutoff, Kaplan–Meier estimator showed a significant difference for the survival ratio (p=0.011).Conclusion: In patients with severe ARDS due to S-OIV-infection, the CT-score has a prognostic value in the prediction of mortality.

Comparison between surgery and radiofrequency ablation for stage I non-small cell lung cancer

2012-02-01

Abstract: Surgical resection remains as the treatment of choice for non-small cell lung cancer (NSCLC) and provides the best opportunity for cure and long-term survival. Minimally invasive percutaneous ablative therapies, such as radiofrequency ablation (RFA) for treating lung cancers, are currently being studied as treatment alternatives. But, to date, there is little information on comparison of therapeutic effects between surgery and RFA in patients with early stage lung malignancy. We aimed to investigate the clinical significance of RFA as an alternative curative modality for the early stage lung cancer through analyzing the long-term mortality of both treatment groups; surgery vs. RFA.Twenty-two patients of stage I NSCLC were included for this comparative analysis. To minimize confounding effects, we conducted a matching process. In which patients of RFA group (n=8) were matched with patients of surgery group (n=14) on the following variables; gender, age (±3 years), tumor node metastasis stage, and calendar year of surgery or RFA (±2 years). The mean survival duration of RFA group and surgery group were 33.18±7.90 and 45.49±7.21, respectively (months, p=0.297). Log-rank analysis showed that there was no significant difference in overall survival (p=0.054) between two groups.These results have shown that RFA can offer the survival comparable to that by surgery to stage I NSCLC patients, especially to the patients impossible for the surgery. This study provides an evidence for the use of RFA as a treatment alternative with low procedural morbidity for inoperable early-stage NSCLC patients.

Aortic volume as an indicator of disease progression in patients with untreated infrarenal abdominal aneurysm

2012-02-01

Abstract: Objective: The maximal diameter of an abdominal aortic aneurysm (AAA) and the change in diameter over time reflect rupture risk and are used for surgical planning. However, evidence has emerged that aneurysm volume may be a better indicator of AAA remodeling. The purpose of this study was to assess the relationship between the volume and maximal diameter of the abdominal aorta in patients with untreated infrarenal AAA.Materials and methods: This was a retrospective study of 100 patients with infrarenal AAA who were followed for more than 6 months. We examined 2 sets of computed tomography images for each patient, acquired ≥6 months apart. The maximal diameter and volume of the infrarenal abdominal aorta were determined by semiautomated segmentation software.Results: At baseline, mean maximal infrarenal diameter was 5.1±1.0cm and mean aortic volume was 139±72mL. There was good correlation between the maximal diameter and aortic volume at baseline (r2=0.55; P<0.001). The mean change in maximal diameter between studies was 0.2±0.3cm and the mean volume change was 19±19mL. However, the correlation between diameter change and volume change was modest (r2=0.34; P=0.001). Most patients (n=64) had no measurable change in maximal diameter between studies (≤2mm), but the change in volume was found to vary widely (−2 to 69mL).Conclusion: In patients with untreated infrarenal AAA, a change in aortic volume can occur in the absence of a significant change in maximal diameter. Additional work is needed to examine the relationship between change in AAA volume and outcomes in this patient group.

Prospective versus retrospective ECG-gated multislice CT coronary angiography: A systematic review of radiation dose and diagnostic accuracy

Zhonghua Sun, Kwan-Hoong Ng — 2012-02-01

Abstract: Purpose: To perform a systematic review of the radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated multislice CT coronary angiography.Materials and methods: A search of Pubmed/Medline and Sciencedirect databases for English literature was performed to identify studies comparing prospective and retrospective ECG-gated multislice CT angiography in the diagnosis of coronary artery disease. Effective dose, dose length product, image quality and diagnostic value were compared between two groups of studies.Results: 22 studies were included for analysis. The mean effective dose of prospective ECG-gated scans was 4.5mSv (95% CI: 3.6, 5.3mSv), which is significantly lower than that of retrospective scans, which is 13.8mSv (95% CI: 11.5, 16.0mSv) (p<0.001). The mean dose length product was 225mGycm (95% CI: 188, 262mGycm) and 822mGycm (95% CI: 630, 1013mGycm) for the prospective and retrospective ECG-gated scans, respectively, indicating a statistically significant difference between these two protocols (p<0.0001). The mean sensitivity and specificity of multislice CT angiography in the diagnosis of coronary artery disease was 97.7% (95% CI: 93.7%, 100%) and 92.1% (95% CI: 87.2%, 97%) for prospective ECG-gated scans; 95.2% (95% CI: 91%, 99.5%) and 94.4% (95% CI: 88.5%, 100%) for retrospective ECG-gated scans, respectively, with no significant difference for sensitivity but significant difference for specificity (p=0.047).Conclusion: Multislice CT coronary angiography with prospective ECG-gating leads to a significant reduction of radiation dose when compared to that of retrospective ECG-gating, while offering comparable image quality and diagnostic value.

Hepatic MR imaging for in vivo differentiation of steatosis, iron deposition and combined storage disorder: Single-ratio in/opposed phase analysis vs. dual-ratio Dixon discrimination

Mustafa R. Bashir, Elmar M. Merkle, Alastair D. Smith, Daniel T. Boll — 2012-02-01

Abstract: Objective: To assess whether in vivo dual-ratio Dixon discrimination can improve detection of diffuse liver disease, specifically steatosis, iron deposition and combined disease over traditional single-ratio in/opposed phase analysis.Methods: Seventy-one patients with biopsy-proven (17.7±17.0 days) hepatic steatosis (n=16), iron deposition (n=11), combined deposition (n=3) and neither disease (n=41) underwent MR examinations.Dual-echo in/opposed-phase MR with Dixon water/fat reconstructions were acquired. Analysis consisted of: (a) single-ratio hepatic region-of-interest (ROI)-based assessment of in/opposed ratios; (b) dual-ratio hepatic ROI assessment of in/opposed and fat/water ratios; (c) computer-aided dual-ratio assessment evaluating all hepatic voxels.Disease-specific thresholds were determined; statistical analyses assessed disease-dependent voxel ratios, based on single-ratio (a) and dual-ratio (b and c) techniques.Results: Single-ratio discrimination succeeded in identifying iron deposition (I/OIronthreshold<0.88) and steatosis (I/OFatthreshold>1.15) from normal parenchyma, sensitivity 70.0%; it failed to detect combined disease.Dual-ratio discrimination succeeded in identifying abnormal hepatic parenchyma (F/WNormalthreshold>0.05), sensitivity 96.7%; logarithmic functions for iron deposition (I/OIrondiscriminator e(F/WFat−0.01)/0.48) differentiated combined from isolated diseases, sensitivity 100.0%; computer-aided dual-ratio analysis was comparably sensitive but less specific, 90.2% vs. 97.6%.Conclusion: MR two-point-Dixon imaging using dual-ratio post-processing based on in/opposed and fat/water ratios improved in vivo detection of hepatic steatosis, iron deposition, and combined storage disease beyond traditional in/opposed analysis.

Comparison of grey matter atrophy between patients with neuromyelitis optica and multiple sclerosis: A voxel-based morphometry study

2012-02-01

Abstract: Purpose: Previous studies have established regional grey matter (GM) loss in multiple sclerosis (MS). However, whether there is any regional GM atrophy in neuromyelitis optica (NMO) and the difference between NMO and MS is unclear. The present study addresses this issue by voxel-based morphometry (VBM).Methods: Conventional magnetic resonance imaging (MRI) and T1-weighted three-dimensional MRI were obtained from 26 NMO patients, 26 relapsing–remitting MS (RRMS) patients, and 26 normal controls. An analysis of covariance model assessed with cluster size inference was used to compare GM volume among three groups. The correlations of GM volume changes with disease duration, expanded disability status scale (EDSS) and brain T2 lesion volume (LV) were analyzed.Results: GM atrophy was found in NMO patients in several regions of frontal, temporal, parietal lobes and insula (uncorrected, p<0.001). While extensive GM atrophy was found in RRMS patients, including most cortical regions and the deep grey matter (corrected for multiple comparisons, p<0.01). Compared with NMO, those with RRMS had significant GM loss in bilateral thalami, caudate, left parahippocampal gyrus, right hippocampus and insula (corrected, p<0.01). In RRMS group, regional GM loss in right caudate and bilateral thalami were strongly correlated with brain T2LV.Conclusions: Our study found the difference of GM atrophy between NMO and RRMS patients mainly in deep grey matter. The correlational results suggested axonal degeneration from lesions on T2WI may be a key pathogenesis of atrophy in deep grey matter in RRMS.

Tumor disease and associated congenital abnormalities on prenatal MRI

2012-02-01

Abstract: Objective: Fetal tumors can have a devastating effect on the fetus, and may occur in association with congenital malformations. In view of the increasing role of fetal magnetic resonance imaging (MRI) as an adjunct to prenatal ultrasonography (US), we sought to demonstrate the visualization of fetal tumors, with regard to congenital abnormalities, on MRI.Materials and methods: This retrospective study included 18 fetuses with tumors depicted on fetal MRI after suspicious US findings. An MRI standard protocol was used to diagnose tumors judged as benign or malignant. All organ systems were assessed for tumor-related complications and other congenital malformations. Available US results and histopathology were compared with MRI.Results: There were 13/18 (72.2%) benign and 5/18 (27.8%) malignant tumors diagnosed: a cerebral primitive neuroectodermal tumor in 1/18, head–neck teratomas in 4/18; ventricular rhabdomyomas in 4/18; a cardiac teratoma in 1/18; a hepatoblastoma in 1/18; neuroblastomas in 2/18; a cystic hemorrhagic adrenal hyperplasia in 1/18; a pelvic leiomyoma in 1/18; sacrococcygeal teratomas in 3/18. Tumor-related complications were present in 13/18 (72.2%) cases; other congenital abnormalities in 3/18 (16.7%). MRI diagnosis and histology were concordant in 8/11 (72.7%) cases. In 6/12 (50%) cases, US and MRI diagnoses were concordant, and, in 6/12 (50%) cases, additional MRI findings changed the US diagnosis.Conclusion: Our MRI results demonstrate the visualization of fetal tumors, with frequently encountered tumor-related complications, and other exceptional congenital abnormalities, which may provide important information for perinatal management. Compared to prenatal US, MRI may add important findings in certain cases.

The effect of nuchal cord on nuchal fold thickness measured in the second trimester

Esra Özkavukcu, Nuray Haliloğlu — 2012-02-01

Abstract: Purpose: To find out whether nuchal cord causes an effect on the nuchal skin fold thickness (NFT) measurements, or not.Patients and methods: A total of 242 fetuses with normal outcomes that had undergone detailed second trimester US scan between 18 and 24 weeks of gestation were included in the study. NFT measurements were made on axial cranial US images passing through the cerebellum and cavum septi pellucidum. To detect nuchal cord, color Doppler imaging was performed on the axial views of the fetal neck. To investigate the differences in NFT measurements of the fetuses with or without nuchal cord, statistical analysis was performed using Mann–Whitney test. P<0.05 was considered statistically significant.Results: The study group was divided into two groups: nuchal cord (+) (n: 26) and nuchal cord (−) (n: 216) fetuses. Mean NFT measurements were 4.66±0.64mm and 4.36±0.79mm for nuchal cord (+) and nuchal cord (−) fetuses, respectively. Median NFT measurement for nuchal cord (+) fetuses was 4.6mm, whereas it was 4.4mm for nuchal cord (−) fetuses. Statistically significant difference was denoted between two groups, in terms of NFT measurements (P=0.049).Conclusion: NFT measurements of fetuses with nuchal cord are higher than the NFT measurements of fetuses without nuchal cord. One can conclude that the nuchal cord (+) fetuses with no other anomalies but increased NFT should be re-scanned to see if the increased NFT resolves in the absence of nuchal cord.

Central venous stenosis of left versus right arm: Its prevalence and effects on image quality in CT of the neck

2012-02-01

Abstract: Objective: The purpose of this study was (1) to evaluate the prevalence of the left and right central venous stenosis by measuring the narrowest area and (2) to assess the effects of the central venous stenosis on perivenous artifacts and reflux of contrast material, in CT of the neck.Materials and methods: Images of a total of 443 CT of the neck with an injection of contrast material into the left (n=249) or right (n=194) arm were retrospectively reviewed. The maximum stenosis area in the central vein ipsilateral to the injection side was measured in each patient. We also graded the perivenous artifacts and reflux of contrast material with 4-point scale. These results were compared between patients with right arm injection and those with left arm injection.Results: The maximum stenosis area in the left arm was significantly smaller than that in the right arm. The stenosis was most frequently identified at the medial clavicular region. The mean scores of the perivenous artifacts and the reflux of contrast material were significantly higher in patients with left arm injection than in those with right arm injection. The perivenous artifacts and reflux of contrast material were more prominent in patients with central venous stenosis (maximum stenosis area <50mm2) than those without stenosis.Conclusions: The image degradation in CT of the neck, due to perivenous artifacts and venous reflux, can be reduced with the right arm injection of contrast material when compared with the left arm injection.

Radiologic identification of disaster victims: A simple and reliable method using CT of the paranasal sinuses

2012-02-01

Abstract: Objective: To assess the reliability of radiologic identification using visual comparison of ante and post mortem paranasal sinus computed tomography (CT).Subjects and methods: The study was approved by the responsible justice department and university ethics committee. Four blinded readers with varying radiological experience separately compared 100 post mortem to 25 ante mortem head CTs with the goal to identify as many matching pairs as possible (out of 23 possible matches). Sensitivity, specificity, positive and negative predictive values were calculated for all readers. The chi-square test was applied to establish if there was significant difference in sensitivity between radiologists and non-radiologists.Results: For all readers, sensitivity was 83.7%, specificity was 100.0%, negative predictive value (NPV) was 95.4%, positive predictive value (PPV) was 100.0%, and accuracy was 96.3%. For radiologists, sensitivity was 97.8%, NPV was 99.4%, and accuracy was 99.5%. For non-radiologists, average sensitivity was 69.6%, negative predictive value (NPV) was 91.7%, and accuracy was 93.0%. Radiologists achieved a significantly higher sensitivity (p<0.01) than non-radiologists.Conclusions: Visual comparison of ante mortem and post mortem CT of the head is a robust and reliable method for identifying unknown decedents, particularly in regard to positive matches. The sensitivity and NPV of the method depend on the reader's experience.

Low field MR imaging of sellar and parasellar lesions: Experience in a developing country hospital

G.I. Ogbole, O.A. Adeyinka, C.A. Okolo, A.O. Ogun, O.M. Atalabi — 2012-02-01

Abstract: Background: Magnetic resonance imaging (MRI), an advancement which followed computed tomography (CT) is expensive and inaccessible in most developing countries. However it is the procedure of choice in evaluating sellar and parasellar lesions. Its major advantages are its superior soft tissue contrast differentiation, its capacity for multiplanar imaging and nonexistence of ionising radiation. Its use is relatively new in Nigeria, a developing economy in Africa. Since its introduction in 2005, it has been utilised extensively for neuroimaging at the University College Hospital (UCH), Ibadan; a large hospital in south-western Nigeria.Objective: To review the role and pattern of low field MR Imaging in sellar and parasellar lesions presenting to a tertiary care centre in Nigeria.Methods: All 62 patients with clinically suspected sellar and parasellar masses, referred to the Department of Radiology, UCH Ibadan for MRI between December 2006 and January 2010 were retrospectively analysed. The examinations were performed using an open 0.2T permanent magnet MR unit. T1W, T2W, T2/FLAIR, TOF and T1W post gadolinium DTPA sequences of the sellar region were obtained.Results: Of the 62 patients, there were 27 males and 35 females. The modal age group was 40–49 years with a mean age of 39.94 years (±16.65 years). Twenty-four cases (38.7%) had histological diagnosis, of which 20 (83.3%) were consistent with initial MRI diagnosis. Pituitary adenomas were the commonest (58.06%) lesions of the sellar and parasellar regions. Others include parasellar meningiomas, cranipharyngiomas, and giant aneurysms. Headache and visual impairment were the major presenting features and showed no significant correlation with tumour size.Conclusion: The use of low field MRI in the diagnostic evaluation of patients with suspected sellar or parasellar lesions in developing countries of low economic resource is commendable as it provides beneficial outcomes in management.

HRCT findings in idiopathic pneumonia syndrome with documentation of the disease course

D. Spira, C. Faul, V. Schaup, S. Wirths, M. Schulze, A. Sauter, M. Horger — 2012-02-01

Abstract: Objective: To analyze extent and patterns of lung involvement in patients with idiopathic pneumonia syndrome (IPS) following allogeneic stem cell transplantation (SCT), and demonstrate their course during therapy.Methods: 14 consecutive patients (age 29–64 years, mean 46.2 years) who experienced IPS after allogeneic SCT (as defined by current guidelines of NIH) were treated with either steroids (n=5), or steroids and the TNF-α blocker etanercept in more severe cases (n=9). CT-scans obtained before, during and after IPS were evaluated retrospectively. Quantification of pulmonary involvement was performed by visual estimation. Surveillance time ranged from 21 to 914 days with a total of 99 CT-scans (2–12 CT-scans per patient) obtained.Results: IPS was mainly confined to the central lung regions (71%) with a bilateral and symmetric distribution (71%). Ground-glass opacity (93%) was the prominent CT-morphologic correlate, whereas concomitant consolidation of lung areas (noted in 43% of patients at the time of maximum infiltrates) only occurred in severe courses of IPS (p<0.01). Favourable courses (50%) showed an earlier peak with respect to extent and CT-attenuation of IPS infiltrates (p<0.01) followed by a rapid decline (median IPS duration 8 days) whereas a significantly more protracted course was observed in severe (unfavorable) cases (median IPS duration 52 days, p=0.01). The death rate in the first and the latter groups (all of the severe cases receiving TNF blockage) was 0% and 43%, respectively. Pulmonary sequelae were recorded in almost all patients during follow-up with fibrotic residues.Conclusion: HRCT-features of IPS are non-specific, but predictable. Response monitoring in IPS can be well accomplished via HRCT and the course of pulmonary infiltrates heralds patient's outcome.

Estimation of radiation exposure of different dose saving techniques in 128-slice computed tomography coronary angiography

2012-02-01

Abstract: Purpose: To estimate the effective dose of cardiac CT with different dose saving strategies dependent on varying heart rates.Materials and methods: For dose measurements, an Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to ICRP 103. Exposure was performed on a 128-slice single source scanner providing a rotation time of 0.30s and standard protocols with 120kV and 160mAs/rot. Protocols were evaluated without ECG-pulsing, with two different ECG-pulsing techniques, and automated exposure control with a simulated heart rate of 60 and 100beats per minute.Results: Depending on different dose saving techniques and heart rate, the effective whole-body dose of a cardiac scan ranged from 2.8 to 9.5mSv and from 4.3 to 16.0mSv for males and females, respectively. The radiation-sensitive breast tissue in the primary scan range results in an increased female dose of 66.7±6.0%. Prospective triggering has the greatest potential to reduce the effective dose to 27.8%, compared to a comparable scan protocol with retrospective ECG-triggering with no ECG-pulsing. Furthermore, the heart rate influences the radiation exposure by increasing significantly at lower heart rates.Conclusion: Due to this broad variability in radiation exposure of a cardiac CT, the radiologist and the CT technician should be aware of the different dose reduction strategies.

Spatial relationship between intrahepatic artery and portal vein based on the fusion image of CT-arterial portography (CTAP) and CT-angiography (CTA): New classification for hepatic artery at hepatic hilum and the segmentation of right anterior section of the liver

2012-02-01

Abstract: Purpose: To clarify the variations of the intrahepatic artery and portal vein and to verify the proper segmentation for the right anterior section of the liver.Materials and methods: CT during arterial portography and CT angiography were performed on 64-slice multi detector row CT in 147 patients. All images were transferred to a workstation for analysis using multi-image-fusion mode. We investigated the spatial relationship between hepatic artery and portal vein in the right hemiliver and the segmentation of the right anterior hepatic artery and portal vein.Results: The spatial anatomy of right hepatic arteries and portal vein was (1) anterior and posterior hepatic artery run superior and inferior to anterior portal vein, respectively (47.6%), (2) one anterior hepatic artery runs superior to and another one runs inferior to anterior portal vein (15%), (3) anterior and posterior hepatic arteries run superior to anterior portal vein (11.6%), (4) anterior and posterior hepatic arteries run inferior to anterior portal vein (7.5%), and (5) one posterior hepatic artery runs superior to and another one runs inferior to anterior portal vein (6.8%).The combined anatomy of right anterior artery and portal vein with regard to segmentation was classified as (1) dorso-ventral (26.5%), (2) dorso-ventral and inferior (10.9%), (3) multiple (18.4%), and (4) superior and inferior segments (1.4%).Conclusion: There are various types of spatial anatomy of intrahepatic artery and portal vein. The hepatic arteries as well as portal veins of right anterior section of the liver could be divided into dorsal and ventral, not superior and inferior.

Omental vascular pedicle sign: Multidetector CT finding useful for diagnosis of an omental mass

2012-02-01

Abstract: Objective: To describe multidetector CT findings of “omental vascular pedicle” sign.Materials and methods: “Omental vascular pedicle” sign was defined as dilated omental vein associated with a mass located in omentum and was observed in 7 patients (5 women, 2 men). Mean age was 45 years. CT examinations and patient records were retrospectively reviewed. CT images were obtained by 16-MDCT (n=1) and 64-dual source MDCT (n=6). Curved planar and volume rendered images were reconstructed from axial images. Diameter of omental vein and drainage site were recorded. Images were evaluated by 2 radiologists in consensus.Results: Pathologic diagnosis of patients with “omental vascular pedicle sign” was omental angiosarcoma (n=1), endometrial adenocarcinoma (n=2), ovarian serous adenocarcinoma (n=2), mixed gonadal tumor (n=1), malignant peripheral sheath tumor (n=1). In 5 patients, omental vein drained into splenic vein and in 2 patients it drained into right gastroepiploic vein. Mean size of omental masses associated with omental vascular pedicle was 7.1×4.5cm (range 15×11cm to 2.7×1.6cm). Mean diameter of omental vein was 3.1mm (range 6–1.5mm). Diameter of the omental vein increased with the increasing size of omental masses and Pearson's correlation coefficient was 0.99.Conclusion: “Omental vascular pedicle sign” can be helpful to objectively diagnose omental masses in patients with primary and metastatic omental tumors.